Argument #1 - We think the open vs closed is just a smokescreen to try and hide the real issue, which is: What's best for the customer? Fragmented vs. integrated. We think Android is very very fragmented and becoming more fragmented by the day. Response - Is being on more platforms in more places bad? Apple is going to have a tiny market share compared to Android long term. This will thrust their mobile location-based advertising and enable them to charge $0 for apps.
Argument #2 - Android OEMs install proprietary user-interfaces to differentiate themselves from the commodity Android experience. The user is left to figure it all out. Compare this with iPhone where every handset works the same. Response - AT&T is a horrible user experience so maybe having the handset experts develop on the platform might solve some of the reception issues.
Argument #3 - Open systems don't always win. Response - Maybe in the short run but not in the long term. Making more money from fewer people is a bad idea. Making less money from more people is a better strategy. I would rather see Google take $50 per handset than Apple making $600 per handset.